#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>

using namespace std;
int main()
{
	string s1;
	string s2("hello world");
	string s3(s2);

	cout << s1 << endl;
	cout << s2 << endl;
	cout << s3 << endl;

	cin >> s1;
	cout << s1 << endl;

	string s4(s2, 6, 15);
	cout << s4 << endl;

	string s5(s2, 6);
	cout << s5 << endl;

	string s6("hello world", 5);
	cout << s6 << endl;

	string s7(10, 'x');
	cout << s7 << endl;

	return 0;
}